The present application is based on Japanese Priority Document 2000-191906 filed on Jun. 26, 2000, the content of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to an ink jet printer head being capable of using conductive ink like water ink and the manufacturing the same.
2. Discussion of the Background
An ink jet printer, comprising a pressure chamber, at least part of which is formed out of piezoelectric member, a nozzle formed in the pressure chamber, and means for applying voltage to the piezoelectric member, so as to jet ink form the pressure chamber through the nozzle using shear mode strain of the pressure chamber generated by applying voltage to the piezoelectric member, has been used so far.
Japanese laid-open publication (unexamined publication) document Hei 8-52872 discloses an ink jet printer head having a pressure chamber covered with an insulation layer consisting of parylene (registered trade mark) or the like by using CVD (Chemical Vapor Deposition), for preventing deterioration of the ink. The document Hei 8-52872 discloses the technique to protect an electrode provided in the pressure chamber by the insulation layer so as to prevent flowing up electricity in the ink in case of using conductive ink so that the ink may be protected from deterioration caused by flowing up electricity therein. The document Hei 8-52872 also discloses the technique to be capable of uniformly forming the insulation layer consisting of parylene or the like on a substrate having complicated and fine shape like inner surface of the pressure chamber of the ink jet printer head or the like by CDV method.
Japanese laid-open publication (unexamined publication) document Hei 8-290569 discloses an ink jet printer head, which applies voltage to an electrode on a piezoelectric member, portion inserted into a pressure chamber of which is coated by polyimide resin by using spin coating method for obtaining stability and durability of the piezoelectric member, to generate displacement of the piezoelectric member toward a nozzle so as to jet the ink contained in the pressure chamber. Thus, the document Hei 8-290569 discloses the technique for preventing the ink to penetrate into the piezoelectric member so as to improve stability and durability of the piezoelectric member.
The drawbacks of the above techniques disclosed in the documents Hei 8-52872 and 8-290569 are now explained.
Because the parylene vapor deposition layer formed by CVD method has small adhesion to the substrate, it is required to execute under finishing like silane coupling finishing when the insulation layer is formed. Thus, the technique disclosed in the document Hei 8-52872 has drawback that the step of forming insulation layer is increased, so that the operability or workability for forming insulation layer is complicated and troublesome.
The technique disclosed in the document Hei 8-290569 improves stability and durability of the piezoelectric member. However, the technique has drawback that the electricity flows up into the ink contained in the pressure chamber via an ink channel in case of using conductive ink because the electrode is attached to the polyimide resin coated on the piezoelectric member.
Accordingly, an object of the present invention is to obtain an ink jet printer head and method for manufacturing the same being capable of using the ink jet printer head for a long time in steady without deterioration of the piezoelectric member and the ink in case of using conductive ink like water ink.
Another object of the present invention is to obtain an ink jet printer head and method for manufacturing the same being capable of using the ink jet printer head for a long time in steady without deterioration of the piezoelectric member and the ink in case of using conductive ink like water ink, even though the piezoelectric member deteriorates polarization property under high temperature.
These and further object of the present invention are achieved by the novel ink jet printer head and method for manufacturing the same of the present invention.
According to the novel ink jet printer head of the present invention, comprising a pressure chamber, at least part of which is formed out of piezoelectric member, to be supplied ink, a nozzle connecting the pressure chamber to outside, an electrode for applying voltage to the piezoelectric member; and an insulation layer, covering the electrode, comprising from organic macromolecule material to be capable of forming by vapor deposition polymerization method. Accordingly, the electrode provided on the piezoelectric member is covered with insulation layer comprising from organic macromolecule material, which is capable of forming by vapor deposition polymerization method, having high adhesion and throwing power, so that the electrodes not disposed on the same plane respectively may be covered with insulation layer.
According to the novel method for an ink jet printer head of the present invention, comprising the steps of forming a pressure chamber, at least part of which is formed out of piezoelectric member, forming an electrode for applying voltage to the piezoelectric member; and covering the electrode with an insulation layer comprising from organic macromolecule material by vapor deposition polymerization method. Accordingly, the electrode provided on the piezoelectric member is covered with insulation layer comprising from organic macromolecule material, which is capable of forming by vapor deposition polymerization method, having high adhesion and throwing power, so that the electrodes not disposed on the same plane respectively may be covered with insulation layer.